Variable: grep-find-use-xargs

How to invoke find and grep.
If `exec', use `find -exec {} ;'.
If `exec-plus' use `find -exec {} +'.
If `gnu', use `find -print0' and `xargs -0'.
Any other value means to use `find -print' and `xargs'.

This variable's value takes effect when `grep-compute-defaults' is called.